[2015 NAHBS] Dean Prototype Titanium Full Suspension Mountain Bike

Dean Bikes had a good looking long travel titanium full suspension prototype frame on display at this year’s North American Handmade Bicycle Show. This new frame is an attempt to maximize titanium’s material properties for a full suspension frame. They are designing this frame as a long travel model for all mountain/enduro/trail riding which they feel is an undeserved category by handcrafted frame builders. The tubing they are using in this frame is grade 9 seamless cold worked stress relived 3/2.5 titanium. The plate chainstays are 1/4″ thick 6/4 titanium plate that are cut with a waterjet. Dean is custom selecting each tube on this frame based on wall thickness and diameter according to strength and stiffness first, before weight.

2015 Dean Titanium 27.5 full suspension

Specs:

27.5 wheels

150mm travel front and rear

66.5 head angle

74 seat angle

437mm chainstays

345mm BB height.

The are offsetting the seat tube forward on the BB to put the rider’s center of gravity more forward for climbing and further aft for descending out of the saddle

The XL sized prototype frame weighed 7.5 pounds with the DBInline. The full bike weighed a little under 29 pounds.

drive side

Suspension Design According To Ian Gowing At Dean:

“The new design uses 1/4″ thick titanium plate chainstays as the lower link in a four bar system. This makes the rear triangle extremely stiff laterally. The bike is constructed much like a simple single pivot, but the vertical chainstay flex lets us dial in our shock rate, anti-squat, and axle path as if it were a much more complicated linkage. The chainstays want to spring open under pedaling forces, making for an extremely efficient climbing bike with loads of traction. This let us dial in our shock rate for an extremely smooth, open feeling ride downhill that is extremely responsive to rider inputs.”

suspension detail

Other info The bike is designed for 1X drivetrains only. Dean says they’re doing this so they can more accurately control the way the suspension reacts to pedaling forces and create a stiff main pivot by using the room above the bottom bracket. They didn’t include ISCG tabs on this proto but the production model with offer them as an option. The bottom bracket is a standard threaded model. The rear end is currently 12×142 but they may tweak the design for 12×148 if there is enough interest. For larger riders this may not be the most wanted option since it can cause heel clearance issues.

bottom bracket area

flex plate detail

Cost and Ordering Details from Ian “The frame will probably be in the $3500-$3800 range including a DBInline shock. All of these frames will be hand built to order, one at a time in our Boulder, CO shop. We will definitely offer limited custom geometry (tt length, st length, ht length, head angle, maybe more). A final version of the frame would include more refined CNC pivot hardware instead of the hand machined parts shown on the prototype. For now we are only planning on a 27.5, 150mm travel design. If this is successful and we see demand for other wheel sizes and travels we will look into these options later.”

This is their first prototype and more testing will be done throughout the summer. They hope to offer it for sale by 2016. They won’t release it however until they are completely satisfied that the frame meets their performance and durability standards.